Potatoes are considered an American staple. They can be used in many different ways, and offer the consumer a wide variety of choices. Developing and propagating some of these varieties starts right here in Colorado.

The San Luis Valley Research Center, which was originally established in 1888, is where many new varieties are developed and tested. The area includes plots, a lab, storage, a greenhouse and testing areas.

The process of creating a new variety takes several years. "This is a process form initial growing to when it goes out to growers, it will be 14 or more needs. The big question is knowing what we will need 14 years from now," said Dr. David Holm, Professor, San Luis Valley Research Center.

To create a new variety, two plants will be crossed. "You start out with the potato flowers. The parents will produce these flowers that have both male and female parts. We will then do controlled pollination and small berries form. Inside those fruits are the true seeds. It's been estimated if you make a cross, you will have to look at a million plants before you find a duplicate," Holm explained.

He continued, "We then germinate that true seed and grow them in the greenhouse. Those will produce tubers, which will then go to the field. We only pick up one percent out of 100,000 plants in the field to continue growing. After several years of selection, we have a variety."

Once this variety is developed, it is the propagated for seed growers to purchase. That is done in the lab in tissue culture.

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"My goal in tissue culture is to grow cultivars in a test tube instead of in soil. I do that to keep my plants clean, disease free, no viruses. This is a lot cleaner environment than in the soil," said Carolyn Keller, Research Associate at the research center.

She keeps many different varieties in tissue culture so that farmers have a wide range of plants to choose from. "I keep about 500 different varieties of potatoes in tissue culture. Every four months I cut them into a new tube, because they use the nutrients that are in the media. I cut it at the node, and put that into the new media. Potatoes are pretty easy to propagate in tissue culture," she said.

She continued, "Then I keep clean varieties and get them tested once a year, and then if a grower wants a variety of potatoes, they tell me what they want, and I will cut them into a vessel. That's then how a grower gets a clean start. Once a year they start with clean plants from me."

Everything she does must be done in a clean environment to keep the plants disease free. "Everything has to be autoclaved and then I work under a hood with tweezers and gloves and scissors. It's really easy to get contamination," stated Keller.

When a grower requests new plants, so propagates the plant until there are 25 plants in a vessel. "The grower then does that increasing. It then goes into the greenhouse, and they put the plants in soil. Some varieties you send 20,000 plants to the greenhouse. They harvest the mini tubers, and then those tubers go into the field," she explained.

The number of tubers that are planted vary from variety to variety, but generally growers will plant around 20,000 tubers per acre. One certified seed grower in the area is Worley Family Farms.

"We are one of nine growers who has their own greenhouse, so we will get vessels from CSU and propagate ourselves," said Bob Mattive, who helps run the farm.

"We raise about 15-20 different varieties, and grow three crops a year, which we harvest mini tubers from. They stay in storage during the winter and we plant them in the spring," he said.

He continued, "The first year is generation one. We keep 100 percent of those G1 tubers. We then plant those back the following year, and those will produce G2. We keep nearly 100 percent of that and plant that back for G3. At that point we start, at harvest time, to begin sizing things and the bigger potatoes will go to packing shed, and smaller to seed storage to sell to commercial growers."

Throughout this process, the potatoes will go through inspections. "They take plant counts and disease counts. We have to meet certain tolerances to stay certified. We also do a winter grow out, where we send tubers to a warm area. Ours go to Hawaii to grow those out quickly, and we get our results back in January or early February so we know how clean those lots are," Mattive said.

Developing new varieties is important to growers. "Some varieties have better economic qualities, are more resistant to disease, need less water, or have better flavor. We want to grow what consumers are wanting. Some have better baking qualities, or are chipping varieties, or processing varieties," he explained.

He added, "We are trying to look at varieties that make higher yields and have lower inputs such as fertilizer or water. We often choose varieties, because of short growing season, that are relatively early maturing. And at the end of the day we want to offer a good product that taste goods."

After all of this, the tubers are also tested to see how they handle storage. "We look at pressure bruises, and we can figure out how long to store different varieties. Immediately after harvest, we look at the skin of the tubers. We use a machine to test how much pressure can be applied, and then we can tell the farmer how long he can store the tubers," said Dr. Sastry Jayanty, Postharvest Physiologist

Developing and growing potatoes isn't always easy. "Right now biggest challenge is drought. We have been in drought since 2002, so the research that is done to find varieties that need less water is really helpful," stated Mattive.

Another challenge they face is consumer preferences. "We have seen in the last ten years a decline in fresh potato consumption. They are not that convenient to prepare, and more meals are being eaten out of the home," he said.

He continued, "And yet, our yield have continued to increase with better varieties. So we end up with surplus supplies, and that drops the price. That's an ongoing challenge nationwide. We try to manage our potato supplies so we continue to sell at a profit."

Even though it takes a lot of time and challenges to overcome, Mattive loves what he does. "It's always amazing as the plants are growing, seeing them grow and produce a crop. At harvest time, it's fun to see the crop come out of the ground and have a nice product," he said.

He added, "We are producing something for people that is a good, healthy product. We are not growing something that will harm people. It's a good product, and has good value for people, and hopefully we can continue to grow it." ❖